1. Field of the Invention
The present invention relates to a zoom lens system, for example, a compact, high magnification zoom lens system suitable for lens shutter camera photographic lenses.
2. Background of the Invention
Zoom lens systems for lens shutter cameras comprising sequentially from the object side a first lens element having positive optical power, and second lens element having negative optical power have been variously proposed to achieve compactness. In such lens shutter type zoom lens systems, it is strongly desirable to achieve high field angle and high magnification while maintaining a compact structure.
Zoom lens systems for lens shutter cameras have been proposed in response to said desires, e.g., Japanese Laid-Open Patent Application Nos. H4-204615 and H5-19166 which disclose zoom lens systems which include a wide angle of field from 70 degrees to 80 degrees. Furthermore, Japanese Laid-Open Patent Application No. H7-252337 discloses a zoom lens system with a zoom ratio of about 3.times..
The zoom lens systems disclosed in Japanese Laid-Open Patent Application Nos. H4-204615 and H5-19166 achieve a wide angle of field up to about 80 degrees at the shortest focal length. Since the number of lens elements are 7 and 9, however, these arrangements cannot be said to be adequate from the perspectives of number of components and compactness.
Moreover, although the zoom lens systems disclosed in Japanese Laid-Open Patent Application No. H7-252337 provides a zoom ratio of about 3.times., this system does not achieve sufficient compactness due to the significantly large amount of movement of each lens element when zooming.